This invention relates to the use of cationic polymers as soil release compounds in cleaners for hard surfaces. The invention also relates to cleaners for hard surfaces which contain these cationic polymers as soil release compounds.
Hard surfaces occurring in the home and in the institutional sector are cleaned with various cleaners which differ from one another both in the concentration of their cleaning-active ingredients, in the form in which they are packaged, for example concentrates, spray cleaners, gels and powders, and in their pH value, for example acidic, neutral and alkaline cleaners. The cleaners are essentially aqueous solutions of surfactants which may contain builders, water-soluble solvents, solubilizers, water-soluble abrasives, etc. as additives. To be able to meet consumer requirements, cleaners of the type in question are required to be effective against all the various soils encountered.
In addition, it would be desirable if the cleaners contained components of the type which facilitate the removal of soil in the second and subsequent applications of the cleaners. Such components are known as soil release compounds. Most soil release compounds are polymeric compounds. These polymers in influence the surface of the articles to be cleaned by positively influencing the removal of soil in the second and all other cleaning cycles. Their mode of action is characterized in that they have a certain tendency in the first cleaning cycle to be deposited onto the cleaned surfaces (substantivity), thus modifying their surface properties. The polymers do not form permanent films, but instead can be removed again, in some cases very easily, with aqueous solutions, for example in the next cleaning cycle. A combination of a marked tendency to wet hard surfaces by a soil release polymer with high stability against removal (in conjunction with soil stabilization in the wash liquor) without reducing the cleaning performance of cleaners would have to be regarded as favorable from the point of view of the consumer.
European patent application EP-A 0 467 472 describes a cleaner for hard surfaces which contains water-soluble anionic, cationic or nonionic polymers as soil release compounds. Polymers containing quaternized ammonium alkyl methacrylate groups in the molecule are mentioned in particular as examples of such polymers. The cleaners described in this document only develop their soil-repelling effect after having already been applied once to the hard surface.
The problem addressed by the present invention was to provide compounds which would act as soil release compounds when used in aqueous surfactant solutions for the manual cleaning of hard surfaces, which would positively influence or at least would not reduce the removal of soil and stabilization of the soil removed in the cleaning liquor during the first application and which would show high surface substantivity towards aqueous solutions, thereby improving the cleaning performance of the cleaner in the event of repeated application.